1. Field of the Invention
The present invention relates to a lancet device whose penetration depth is adjustable. The lancet device is adapted to be substantially inexpensive to manufacture and easy and safe to use by physically impaired individuals who take their own blood samples.
2. Description of Background Information
The field relating to disposable and reusable lancet devices is substantially crowded. U.S. Pat. No. 5,464,418 to SCHRAGA, the disclosure of which is incorporated by reference herein in its entirety, discloses a reusable lancet device having an elongate triangular housing and triangular cap segment.
Lancets which allow adjustment of the penetration depth include U.S. Pat. No. 5,318,584 to LANGE et al., the disclosure of which is incorporated by reference herein in its entirety. This document discloses a blood lancet device for withdrawing blood for diagnostic purposes. The penetration depth of this blood lancet device may be adjusted by adjusting the position of a sealing cap relative to a housing.
U.S. Pat. No. 4,924,879 to O'BRIEN, the disclosure of which is incorporated by reference herein in its entirety, discloses a blood lancet device. The penetration depth may be adjusted by adjusting the position of a skin surface sensor which may be a small socket head screw.
U.S. Pat. No. 5,613,978 to HARDING, the disclosure of which is incorporated by reference herein in its entirety, discloses an adjustable tip for a lancet device. The penetration depth of this lancet may be adjusted by adjusting the position of an outer cylindrical sleeve relative to an inner sleeve.
U.S. Pat. No. 4,895,147 to BODICKY et al., the disclosure of which is incorporated by reference herein in its entirety, discloses a lancet injector which includes an elongate tubular housing with a penetration depth selector provided thereon. Rotation of the penetration depth selector causes a control member to contact different contact edges to thereby control the distance that a lancet tip protrudes through a central opening.
U.S. Pat. No. 1,135,465 to POLLOCK, the disclosure of which is incorporated by reference herein in its entirety, discloses a lancet. The distance that a plunger is allowed to move forward may be changed by an adjustable movement limiting or regulating collar.
Canadian Patent No. 523,078, the disclosure of which is incorporated by reference herein in its entirety, discloses a surgical device for use in the treatment of snake bites. The surgical device includes a lance or blade whose penetration depth may be adjusted by inserting or removing a stop bar from the path of the lance or blade.
SUTOR et al., "Bleeding from Standardized Skin Punctures: Automated Technic for Recording Time, Intensity, and Pattern of Bleeding", A.J.C.P., Vol. 55, pp. 542-549 (May 1971), the disclosure of which is incorporated by reference herein in its entirety, discloses a Mayo automatic lancet. A knurled thumb screw allows adjustment of depth of cut by regulating distance between a plunger and a striking head by means of a millimeter scale.
Although there are several devices which allow adjustment of the penetration depth, there are important factors relating to the safe and effective use of lancet assemblies which have not been addressed by such devices. Specifically, there is a need for a lancet device having an adjustable penetration depth whose penetration depth adjustment mechanism is reliable and difficult to accidentally change.